What is Alpha: Definition and 474 Discussions

Alpha (uppercase Α, lowercase α; Ancient Greek: ἄλφα, álpha, modern pronunciation álfa) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , which is the West Semitic word for "ox". Letters that arose from alpha include the Latin letter A and the Cyrillic letter А.

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  1. B

    Hermicity of alpha (dirac equation)

    Homework Statement Show that \mathbf\alpha\equiv\left[\begin{array}{cc} 0&\mathbf\sigma\\ \mathbf\sigma&0\end{array}\right] is hermitian. The Attempt at a Solution My first instinct was to say that \mathbf\sigma must be equal to its complex conjugate (as it would if it was a scalar...
  2. K

    Is the ionising power of alpha particles greater than that of gamma

    I request for help in understanding the following: Q1. Why is the ionising power of alpha particles greater than that of gamma rays? Q2. Why does the ratio of neutrons to protons in a nucleus increase after the emission of an alpha particle? I would like to have a quantitative...
  3. T

    Alpha and theta represent the same known or unknown angle?

    I was wondering in terms of a mathematical approach to physics, whether alpha and theta represent the same known or unknown angle in the triangles. Ex.. Vi = vo(sin)(theta) or Vi = vo(sin)(alpha)
  4. S

    Alpha Decay of Actinium 223

    Homework Statement Find which of the α and β decays are allowed for 223Ac. (Determine the disintegration energy Q for each decay which is allowed, and calculate the binding energy B against each decay which is not allowed.) Homework Equations Q=(Parent mass-Daughter mass-alpha particle mass)c^2...
  5. S

    Kinetic Energy of a daughter Particle in Alpha decay.

    Homework Statement How much kinetic energy does the daughter have when Samarium 148 undergoes alpha decay from rest?Homework Equations Q=(Mparent + Mdaughter + Malpha)c^2=Kd+Kalpha Kalpha=MdQ/(Md+Malpha) The Attempt at a Solution I started with the fact that samarium 148 would become...
  6. M

    Radiation Emission Spectrums for Alpha, Beta, and Gamma

    Homework Statement I'm taking a nuclear physics seminar, and I'm wondering what causes the differences in the energy spectra between alpha, beta, and gamma emissions. Specifically, why is dispersion for energy values in alpha radiation so different from that of beta? I'm also looking for a...
  7. Jonathan Scott

    Lyman alpha forest different for different objects?

    I was wondering how the distribution of Lyman alpha absorbers (as seen in the "forest" of absorption lines of a quasar spectrum) varies with red-shift (corresponding to evolution with the age of the universe). I've found various sources which mention in passing that the frequency of absorbers...
  8. U

    Alpha & Beta Glucose: How to Differentiate

    Hi all, I find difficulties in recognizing between alpha and beta Glucose. Can anybody explain briefly how can I differentiate between them ?
  9. Monocerotis

    Discover Wolfram Alpha - "Oh My!

    Wolfram Alpha - oh...my... Am I the last person on this planet to find out about this website ? It's freaking amazing ! check it out if you've never heard about it. http://www.wolframalpha.com
  10. J

    Travel in space to Alpha Centuri

    I'm having a bit of a debate on traveling to AC. I was wondering if someone can post calculatons to show how long it would take traveling at 1g accelaration, and how much energy would be needed including any relativistic influences. Thanks
  11. H

    Finding Magnetic Field of Alpha Particle in a Circle

    Homework Statement An alpha particle is moving at constant speed in a circle, perpendicular to a uniform magnetic field, making a revolution every 60 nanoseconds. Its speed is non-relativistic What is the numerical magnitude of the magnetic field in T ? Homework Equations alpha...
  12. T

    Understanding the Charge on Alpha Particles

    Just wondering, why does the alpha particle which is basically just a helium atom have a 2+ charge on it when you write it although the electronic configuration of the alpha particle is exactly the same as a helium atom?
  13. J

    Explaining Alpha Decay Energies in 232Th

    Homework Statement I got ask the following question, and i don't know the answer. Why in a rdioactive decay of 232Th by alpha emission, the alpha particle can have energy 4.01 Mev and 3.95 Mev? Homework Equations The Attempt at a Solution I look up this website and i found...
  14. W

    Scattering of alpha particles

    In air, high angle scattering of alpha radiation from Am241 is almost non existent. When a sample is pulled away from a detector the detection rate drops as 1/r^2. But if a thin aluminium foil is inserted in the path almost half of the radiation disappears somewhere else, it do not reach...
  15. M

    Alpha centuri .4 light year relative to who?

    Alpha centuri...4 light year relative to who? Hi, Here it goes. Suppose it takes 4 light years to get to alpha centuri. So if I could travel at 99.99999% the speed of light and the people on Earth remains stationary(as in moving very slowly which is << C). So does my clock shows 4 years...
  16. T

    How many alpha particles strike a plane target in 8 seconds?

    Homework Statement Assume a steady stream of α particles travels with a constant energy of 20 MeV and carries a current of 2.5 μA. a) If the beam is directed perpendicular to a plane target, how many α's will strike this target in 8 seconds? b) At any given instant, how many α's are in a...
  17. D

    Alpha decay short half lives correspond to large disintegration energies

    Homework Statement i) Explain why in alpha decay short half lives correspond to large disintegration energies. ii) Determine the energy release during the alpha decay of 238U to 234Th. The mass of 238U is 238.0508mu, the mass of 234Th is 234.0436mu, and the mass of 4He is 4.0026mu...
  18. M

    The Brogile wavelength of an Alpha particle

    Homework Statement An alpha particle of energy 5.78 MeV is emitted from a particular nucleus. Calculate the de Broglie wavelength of the alpha particle. How does it compare with the nuclear diameter, which is known to be approximately 2x10−14 m. Homework Equations E=h/p and E=hf...
  19. T

    Hydrogen Atom and Relatavistic Corrections - What does this Alpha mean

    Homework Statement Okay, I need to work out the Relativistic corrections for an atom, using the First KE Term and the Darwin Term: Calculate the energy shift of the protonium groundstate due to the relativistic correction to the kinetic energy and the Darwin term and compare it to...
  20. S

    Why Does $\Sigma_{i=1}^n x_i(y_i - \alpha - \beta x_1) = 0$ Follow?

    Why does it follow from \frac{d}{d\beta}(-\Sigma_{i=1}^n[\frac{(y_i - \alpha - \beta x_i)^2}{2 \sigma^2}]) = 0 that \Sigma_{i=1}^n x_i(y_i - \alpha - \beta x_1) = 0 ?
  21. D

    Comparing KE of Electron & Alpha Particle w/ Same R of Curvature

    Homework Statement Suppose that I want to compare the Kinetic Energy of an electron to the Kinetic Energy of an alpha particle if they both have the same radius of curvature in a magnetic field. Homework Equations qvB = mv^2/r KE = 1/2 mv^2 The Attempt at a Solution I am...
  22. C

    Energy of alpha particle and quantum tunneling

    Homework Statement Alpha decay typically involves an alpha-particle of 5-6Mev. How can this be explained using quantum mechanics? Homework Equations The Attempt at a Solution I think I need to work out the potential barrier and then work out how much KE an alpha particle has...
  23. S

    Secondary radiation from alpha particles?

    This is probably a naive question, but I've been trying for awhile to figure it out myself and just don't have the background to do so. I know that beta particles can generate x-rays through bremsstrahlung processes, and that some materials excited by alpha particles can generate light through...
  24. W

    Estimating Alpha Particle Speed & Kinetic Energy in a Heavy Nucleus

    Homework Statement Use the uncertainty principle to estimate the minimum speed and kinetic energy of an alpha particle confined to the interior of a heavy nucleus. Homework Equations delta_p*delta_r = h_bar/2 for minimum momentum p = mv for non-relativistic particle, the alpha...
  25. K

    Californium-242 nucleus 242/98 Cf decays via alpha decay

    Hey I'm new to this forum, just want to say hi! I'm not sure if this is the rite place to put this but sry if i posted in the wrong section >.< I'm actually working on an assignment in my natural science course and I'm stuck on this question cause I'm not sure how to use the variables in the...
  26. 3

    Ratio kinetic energy of alpha particle / kinetic energy of proton

    Homework Statement A photon and alpha particle are accelerated from rest through the same potential difference. After acceleration what is the ratio kinetic energy of alpha particle / kinetic energy of proton? Homework Equations I guess I have to use eV = 1/2mv^2 The Attempt at a...
  27. W

    Half Life / Alpha Decay Question - No IDea

    Half Life / Alpha Decay Question -- No IDea Homework Statement A space rock contains 3.20 g of 147 62 Sm and 0.110 g of 143 60 Nd. 147 62 Sm alpha decays to 143 60 Nd with a half-life of 1.06 1011 yr. If the rock originally contained no , how old is it? Homework Equations ...
  28. Z

    Max Energy of Electron After Collision with Particle: 5.0 MeV Alpha

    Homework Statement A particle (nonrelativistic) of mass M and with kinetic energy E0 collides with an electron at rest of mass m. Show from elementary considerations (i.e. rst year physics) that the maximum energy of the electron after the collision is E0(4m/M). Determine this energy for...
  29. P

    Alpha Particle shot at Nucleus Energy

    Homework Statement What energy alpha particle would be needed to just reach the surface of an Al nucleus if its radius is 4fm? *This problem is found in a section dealing with Rutherford's gold foil scattering experiment, so take it in that context. Homework Equations F=(kqQ)/r2 The Attempt...
  30. J

    Integral function of order alpha

    What does it mean when a function is said to be an integral function of order \alpha? \alpha is some real constant. I encountered this terminology in the context of complex analytic functions.
  31. P

    Elastic collision between an unknown mass and an alpha particle

    Homework Statement In an elastic collision between an alpha particle and an unknown nucleus at rest, the alpha particle was deflected through a right angle and lost 40 percent of its energy . Identify the mysterious nucleus. Homework Equations...
  32. W

    Atomic Decay: Charged Element After Alpha Helium Release?

    In atomic decay, when an atom decays and releases the (Alpha) Helium nucleus, the atom left behind changes to the element 2 Proton Numbers prior. So is this new element charged? because the electrons stay behind, or do they go? and if so, where to and how?
  33. K

    Supremums 'alpha' and 'beta' problem

    Homework Statement Let A, B,be two non empty sets of real numbers with supremums 'alpha' and 'beta' respectively, and let the sets A+B and AB be defined by: A+B={a+b / a belongs to A, b belongs to B}, AB= {ab / a belongs to A, b belongs to B}. Show that alpha+beta is a supremum of A+B...
  34. L

    Collision of Alpha particle with a Gold Nucleous

    Homework Statement An alpha particle (a helium nucleus, containing 2 protons and 2 neutrons) starts out with kinetic energy of 9.5 MeV (9.5106 eV), and heads in the +x direction straight toward a gold nucleus (containing 79 protons and 118 neutrons). The particles are initially far apart...
  35. L

    Alpha Particle-Gold Nucleus Collision: Solving for Initial and Final Momentum

    Homework Statement An alpha particle (a helium nucleus, containing 2 protons and 2 neutrons) starts out with kinetic energy of 9.5 MeV (9.5106 eV), and heads in the +x direction straight toward a gold nucleus (containing 79 protons and 118 neutrons). The particles are initially far apart...
  36. P

    Alpha Lipoic Acid polymerization question

    I am taking R-Alpha Lipoic Acid (RALA) as a supplement, however apparently it's very unstable and polymerizes at about 40-50 degrees C and becomes unabsorbable. Apparently it also polymerizes when it reaches the stomach. There are also stabilized forms such as Na-RALA and K-RALA. Now what i want...
  37. H

    What is the correct speed of alpha particles directed towards lead foil?

    Homework Statement A beam of α particles with energy/particle = 2.86 MeV is directed towards lead foil. What is the speed of the α particles? Homework Equations E = 1/2 mv^2 v = SQRT(2E/m) v = SQRT((2)(2.86E+6)(1.602E-19) / (1.673E-27) ) = 23403526 m/s = 0.078c but the ans is 0.039c...
  38. N

    How many particles have momentum in a specific interval?

    Homework Statement a pulse 1 m long contains 1000 α particles.at t=0,each α particles in the state ψ(x,0){1/10e^(-ik_0 ) lxl≤50cm,k_0=π/50 and 0 for elsewhere,} at t=0 ,how many particle s have momentume in the interval 0<hk<hk_0? Homework Equations introduction to quantum...
  39. S

    Alpha particle deviation from gold foil (Rutherford Scattering)

    1. Homework Statement The alpha particles used by Rutherford had a kinetic energy of 7.7 MeV and, for a head-on collision would get to within a distance of 3×10-14m of the centre of the gold nucleus. However the actual radius of a gold nucleus is approximately 7×10-15m. 2. Homework Equations...
  40. J

    Calculating the Year Length of Planet Y Around Alpha

    Planet X orbits the star Alpha with a 'year' that is 200 Earth days long. Planet Y circles Alpha at nine times the distance of planet X. How long is a year on planet Y? I know that I have to use the kepler's law : T^2 = (4pi^2/GM)r^3 but I'm not too sure how to do solve this... Please...
  41. T

    How to Prepare Geometry Lectures for Mu Alpha Theta Competition?

    I don't know how many of you have heard of Mu Alpha Theta, but for those who haven't, it's a high school and two-year college math competition. -- Shameless plug: Middleton, my high school, won 7th in the nation in July! Go tigers! -- I'm taking Algebra 2 this year, but one of our coaches...
  42. C

    Taking Apart an Alpha Particle

    Homework Statement An alpha (α) particle is the nucleus of a 4He atom and consists of 2 neutrons and two protons bound together. Let's take apart an α particle, step by step, looking at the energy required at each step. To do so, we may want to use the following atomic masses: 4He: 4.0026 u...
  43. P

    Ionizing particles (alpha & beta)

    I think I understand the impact that an alpha particle can have on living tissue. Not having electrons in it valence it would be very reactive - stripping electrons from atoms or molecules it bumps into (assuming it made its way in a biotic host). But how does a beta particle ionize an atom...
  44. U

    Should we send interstellar probe to Alpha Centauri?

    Should we send an interstellar (unmanned) probe to Alpha Centauri? Would it be much more expensive than a manned mission to Mars? According to Wikipedia, velocities as high as 0.10c are possible with hydrogen bombs. That means that ~40 years flight time to the nearest star would be possible...
  45. C

    Real Roots of the Quadratic Equation for all Alpha Values

    Show that the equation x2 + (3\alpha - 2)x + \alpha(\alpha - 1) = 0 has real roots for all values of α \in IR. How do i do this? Do i just use the b2 + 4ac \geq 0 ?
  46. A

    Solving Homework Problem on \alpha = 37, m1 = 10 kg

    Homework Statement \alpha = 37, m1 = 10 kg Also attachment. Homework Equations The Attempt at a Solution ok, the first question is to find m2 when the system is in rest and the second one is to find the acceleration when m1 = m2. I found 3 equations: n1 = m1 * g * cos(\alpha...
  47. Ivan Seeking

    Beating the Alpha Skunk: My Office Solution

    A skunk has gotten wise to my office situation and learned to use the cat door. This has been going on for a couple of months, and surprisingly the only real problem is the cost in cat food. But there is always the concern that, sooner or later, it is going to blast my office and/or cat. In the...
  48. Ookke

    Win Alpha Centauri Lottery - Journey from Earth to Alpha Centauri

    A rocket is preparing for journey from Earth to Alpha Centauri. The Earth and Alpha Centauri systems are at rest with each other and have syncronized their clocks to time t=0. ________E__________________________________________________A (distance: 4 ly) ________R Rocket speed is known...
  49. M

    Is covering a high radioactivity alpha source with a low Z material safer?

    Hi all! I have the following question to solve and it's getting me down. Suppose we have an alpha source with very high radioactivity (such as 100kCu) in our workspace. Even though we know that the range of alpha particles in air is about 4 cm and we try to stay away from the source and...
  50. E

    Finding the potential difference of an alpha particle.

    1. Through what potential difference (\DeltaV) would you need to accelerate an alpha particle, starting from rest, so that it will just reach the surface of a 15 x 10^(-15) m ^{238}U nucleus? 2. KE = q\DeltaV E = \gamma_{p}mc² r = \frac{mv}{qB} 3. Ok, I feel like I am close to what I really need...
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